问题 计算题

当交叉路口的绿信号灯亮时,一辆客车以a="2" m/s2的加速度由静止启动,在同一时刻,一辆货车以v0="10" m/s的恒定速度从它旁边同向驶过(不计车长)。求:

①客车追上货车时离路口多远?

②在客车追上货车前,两车间的最大距离是多少?

答案

 

题目分析:(1)货车车匀速运动,客车初速度0的匀加速直线运动

客车追上货车时         3分

代入数据得,      1分   

.        2分

(2)两车距离最大时,两车应具有相等的速度,即       3分

代入数据,得.        1分

          2分

填空题
阅读理解

One day, when I was in college, a dishonest-looking character approached me in the student union with a leather jacket he wanted to sell. It was a beauty: buttery smooth cowskin, with artfully sewed lines and long leather fringes (穗).

I can’t remember what the price was, but it was apparently too little for such a jacket. Even as I paid the money that day, I knew something wasn’t right. Surely, a couple of days later, the jacket’s real owner, a student about my age came to me as I was on my way to class.

“That’s my jacket,” he said, “and I want it back.”

“No way,” I answered. “I paid for it, and I have no idea if it’s yours. It’s mine.”

He didn’t challenge me, and I left, but the uneasiness(不安) I had about my new possession now had a visible face. A few days later, riding my bike across campus, I saw the real owner standing on the sidewalk. I rode over, took the jacket off, handed it to him said I was sorry, and rode off without another word. More than the weight of the jacket had been lifted from my shoulders.

We’re all human, which means that sometimes we do things we shouldn’t do or say things we shouldn’t say. Sometimes we realize too late that our actions have been hurtful to somebody else. When these hard times occur, the best response --- the only response, really --- is, “I’m sorry.”

Admitting a wrongdoing, as soon as possible and frankly, helps the other person begin to heal. But just as important, it cleans up our own soul and sets us free.

That is a small price to pay for a clear conscience.

小题1:The author bought the leather jacket from the man in the student union because ______   .

A.it was charged at a reasonable price

B.it was a very attractive jacket

C.he was in great need of clothing

D.he was happy to find such a bargain小题2:The phrase “had a visible face” in the passage probably implies(暗含) “______  ”.

A.started to bother me badly

B.might be clearly expressed

C.began to give me away openly

D.could be instantly melting away小题3:Giving the leather jacket back to the real owner, the author ______    .

A.offered his forgiveness

B.felt very much relieved

C.rode away unwillingly

D.realized his wrongdoing小题4:What is the author’s purpose of this writing?

A.To encourage the readers to admit errors honestly.

B.To show the readers the reality of his college life.

C.To give the readers a lesson on how to say sorry to others.

D.To tell the readers a story that once happened at college.